As is known, filling machines for products in the form of powder or granules or other similar products have a fixed structure that supports a conveyor of containers, constituted typically by a rotating carousel, which supports a plurality of supporting devices on which the containers to be filled are arranged.
Above each one of these supporting devices there is a respective head for dispensing the product, which is caused to fall onto the underlying container so as to fill it progressively.
In some filling machines, known as weight-filling machines, the container supporting devices are connected to the remaining structure of the machine by the interposition of load cells, designed to supply a signal that is proportional to the weight of the product poured into the containers, so as to allow the determination, by means of appropriate control systems, that the weight of the desired product inside the containers has been reached.
One drawback of this type of machine resides in the fact that the product that falls into the container tends not to distribute uniformly inside it but rather to accumulate in the region where it falls into the container, with the risk of reaching and rising above the upper rim of the container long before all of the product has been spilled into said container.
For solving this drawback, devices for supporting containers have been proposed which are provided with actuation means that are capable of vibrating the containers during their filling process so as to obtain a more uniform filling of the containers with the dispensed product.
Currently known supporting devices of this type operate by means of vibrating motions that have a radial direction with respect to the rotation axis of the carousel thanks to the operation of mechanical elements provided with a system of antagonist elastic elements.
These devices, besides not ensuring the same reliability over time, due to the loss of the mechanical characteristics of the elastic elements, do not allow an easy variation of the vibration frequency.
Moreover, the vibrating motions induced in known supporting devices tend to influence the response of the load cells associated therewith, with consequent distortion of the signal that arrives from said load cells due to the addition of force components that alter the information relating to weight.